A “Cone of Silence” protects junk forensic science and allows it to survive in criminal courts.

Today’s subject is a brief look back at how pattern evidence from bruised human skin got into the case law of every state in the US. Its not a pretty process, as I describe below.

Scientists learn from their past studies which includes unsuccessful experimentation. The recognition and use old data to construct new theories and experimental hypotheses is part of  scientific progress. But scientific tenets don’t seem to apply to dentists who deal in bitemark IDs. They  liken themselves as still being relevant for courts. One caveat: these days they disappear when DNA is available

Assumptions of personal rather than fact of empirically proven nature were and still are acceptable by judges and rules of evidence. One past AAFS/ABFO president (among other forensic types) said, after the 2009 NAS Report on bitemarks laid out all its “scientific” mumbo-jumbo”, that hard scientific proofs (meaning testing that allows repeatability among numerous research agencies) are unattainable in forensics regarding this type of evidence. Carrying such logic further, this implies courts should still rely on expert testimony founded on opinions of “reasonable certainty.”  I think he forgot how this lawyer-developed certainty of opinion has led to dozens of innocent defendants ending up in prison. Hundreds of bitemark cases from past decades seem cloaked in some “cone of silence” protection created by both the AAFS and its underling bitemark-board, the ABFO.  At this point, all we have are the cases summaries from judicial literature.

Here is one case.

The dentists mentioned in the following 1980 appellate acceptance of the bitemark craft were lauded as “crime fighters.” Their progeny of today wish for a return to glory.

I will just highlight the “reasonable certainty”statements in this often-cited case of expert statements which never have been scientifically proven.  A few comment will be included.

State v. Sager, 600 SW 2d 541 – Mo: Court of Appeals, Western Dist. 1980

“Dr. Luntz concluded that the bite mark reflected in the photograph of the breast of the victim was beyond a reasonable doubt placed upon the victim’s breast by appellant.”

A typical “I see it, therefore it is” statement.

“Dr. Furness testified he had viewed approximately 150 bite mark cases and that if one dissimilarity appeared, this would exclude the person as a suspect.”

“Dissimilarities” between any purported bite evidence and a suspect are now allowed to be dismissed by merely saying “this is caused by dynamic biting force and pressure. (California v. Eric Frimpong. 2008.)  Defendant was convicted. 

“He further stated that although it might appear to the layman that bite marks appear similar, it is impossible for two humans to make exactly the same bite mark.”

Classic statement that has yet to be proven. It hints to the following “leap of faith.”

“He explained his analysis depicted in the visual aids used as exhibits explaining how the teeth corresponded to the bite marks, describing the reasons for assigning each of the points of similarity. The points of similarity were assigned on the basis of corresponding positions, high spots, spacing irregularities and outer surfaces of the teeth.”

This analogy to fingerprint  comparisons has been used over the decades by bitemark dentists for its powerful effect. It rapidly falls apart, as there has never been a successful study or series of studies on the subject. An attempt in 1986 by the ABFO ultimately was rejected due to lack of repeatability amongst its members. 

“He denied that embalming a body would distort a bite mark.”

Never been tested. Forensic pathologists would find this an amazing statement. Used numerous times in many precedent setting bitemark cases. 

“He concluded that in his opinion, “based upon reasonable medical and dental certainty” that the person from whom the casts were obtained inflicted the wound depicted in the colored photograph. It was his opinion that appellant was the perpetrator of the bite mark.

While the experts in the instant case arrived at opposite ends of the analysis spectrum in their interpretation of the particular evidence, one common denominator emerges from their voluminous testimony and the extensive number of exhibits.”

“That common denominator is that forensic odontology, inclusive of bite mark identification, is an exact science. It is exact in the sense that through acceptable scientific procedures, an expert can form an opinion useful to the courts in their quest for the truth.”

Remember this point, Sloan is still “good law” in most states.




About csidds

Dr. Michael Bowers is a long time forensic consultant in the US and international court systems.
This entry was posted in Uncategorized. Bookmark the permalink.

1 Response to A “Cone of Silence” protects junk forensic science and allows it to survive in criminal courts.

  1. csidds says:

    Reblogged this on FORENSICS in FOCUS @ CSIDDS | News and Trends and commented:

    The bitemark experts once AGAIN, promise that they will do better. Read the following recent website posting from their head honcho. As usual, nothing about how where all this new reliability comes from. All his “good” cases sums his defense. “The ABFO has excluded far more people than they ever included.” Of course, the ones they included in 24 cases were innocent and the ones excluded never knew how close they came to their doom. This self-serving ratio of Loomis’ “risk vs benefit” statement is off-the cuff. His audience is small. and growing smaller.
    The New York Times printed an article on 9/16/2014 faulting “bite-mark forensics.” It highlights an appeal recently filed by the Mississippi Innocence Project with the Mississippi Supreme Court, of 22 year old case in which bite mark testimony was provided by Dr. Michael West. Like every news article, there are misstatements and some erroneous information is given. In particular, the author parrots the flawed Innocence Project publicity that 17 people previously convicted based on “expert bite matches” have been exonerated by DNA evidence. The IP often uses the number of 24 so it least the number is down a bit, but in actuality the number is 10, and of these, five of the opinions were not “match” as the article mentions but a lesser opinion. While any number of wrongful convictions is unacceptable and we are all cognizant of the fact that some terrible mistakes have been made in the past, we cannot ignore the fact that hundreds of positive outcomes have occurred throughout the country wherein bite mark evidence played a crucial role in the judicial process to assist the triers of fact. The ABFO continues to make changes to ensure accuracy of expert opinions. The ABFO has developed the Bitemark Analysis and Comparison Decision Tree, is continuing to develop a bitemark proficiency examination, has significantly raised the bitemark and other requirements for examination eligibility for new candidates, requires recertifying diplomates to take a recertification examination and has revised the standards, guidelines and terminology for bitemark analysis.

    Peter W. Loomis, DDS, D-ABFO
    President – American Board of Forensic Odontology

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s